Hydra Open Cluster

Pierre Moutounet-Cartan
Mar 24
1 min read

About this object

Messier 48 (M48/NGC 2548), a 450-million-year-old open cluster in Hydra, lies 2,500 light-years away and spans 23 light-years across, containing about 80-100 stars dominated by B-type giants and A-type main-sequence stars. With a near-solar metallicity ([Fe/H] ≈ -0.06) and apparent magnitude of +5.8, this gravitationally loose cluster—currently undergoing tidal disruption—serves as an excellent laboratory for studying intermediate-age stellar evolution and galactic dynamics. Visible to the naked eye under dark skies but best resolved with binoculars, M48's scattered structure contrasts with denser clusters like M44, offering observers a glimpse of a stellar family slowly dispersing into the Milky Way's disk.